<?xml version='1.0'?>   
    <!DOCTYPE rfc SYSTEM 'rfc2629.dtd' [ 
    	<!ENTITY rfc2629 PUBLIC '' 'http://xml.resource.org/public/rfc/bibxml/reference.RFC.2629.xml'> 
		]>
<?rfc strict="yes"?>
<?rfc toc="yes"?>
<?rfc tocdepth="4"?>
<?rfc symrefs="yes"?>
<?rfc sortrefs="yes"?>
<?rfc compact="yes"?>
<?rfc subcompact="no"?>
<rfc category="std" docName="draft-xiong-rtgwg-precise-tn-requirements-01"
     ipr="trust200902">
  <!-- ***** FRONT MATTER ***** -->
  <front>
    <title abbrev="The Requirements for Precise Transport Networking">The Requirements for Precise Transport Networking</title>
	
	<author fullname="Quan Xiong" initials="Q" surname="Xiong">
      <organization>ZTE Corporation</organization>

      <address>
        <postal>
          <street>No.6 Huashi Park Rd</street>
          
          <city>Wuhan</city>
          
          <region>Hubei</region>
  
          <code>430223</code>

          <country>China</country>
        </postal>

        <phone></phone>

        <email>xiong.quan@zte.com.cn</email>
      </address>
    </author>
	
    <author fullname="Peng Liu" initials="P" surname="Liu">
      <organization>China Mobile</organization>

      <address>
        <postal>
          <street></street>
          
          <city>Beijing</city>
          
          <region></region>
  
          <code>100053</code>

          <country>China</country>
        </postal>

        <phone></phone>

        <email>liupengyjy@chinamobile.com</email>
      </address>
    </author>
    
   <date month="November" year="2020"/>	
    <area>Routing</area>
    <workgroup>RTGWG</workgroup>
    <keyword></keyword>
    <abstract>
    
	<t>The future networks not only need to offer the Service Level Agreements (SLA)
	guarantees such as low lantency and jitter, low packet loss and high reliability, 
	but also need to support the precise services such as flexible resource allocation
	and service isolation. This document proposes a set of performance requirements
	and precise properties for Precise Transport Networking in various industries such 
	as 5G networks.</t>
	 
	 
    </abstract>
  </front>

  <!-- ***** MIDDLE MATTER ***** -->

  <middle>
  
    <section title="Introduction">
	
	<t>5G network is oriented to the internet of everything. In addition to the 
	Enhanced Mobile Broadband (eMBB) and Massive Machine Type Communications(mMTC) 
	services, it also supports the Ultra-reliable Low Latency Communications (uRLLC) 
	services. The uRLLC services cover the industries such as intelligent electrical 
	network, intelligent factory, internet of vehicles, industry automation and other
	industrial internet scenarios, which is the key demand of digital transformation 
	of vertical domains. These uRLLC services demand SLA guarantees such as low 
	latency and high reliability and other deterministic and precise properties.</t>
	
	<t>For the intelligent electrical network, there are deterministic requirements 
	for communication delay, jitter and packet loss rate. For example, in the 
	electrical current difference model, a delay of 3~10ms and a jitter variation 
	is no more than 100us are required. The isolation requirement is also important.
	For example, the automatic operation, control of a process, isochronous data 
	and low priority service need to meet the requirements of hard isolation. In
	addition to the requirements of delay and jitter, the differential protection 
	(DP) service needs to be isolated from other services.</t>
	
	<t>The industrial internet is the key infrastructure that coordinate various 
	units of work over various system components, e.g. people, machines and things 
	in the industrial environment including big data, cloud computing, Internet of 
	Things (IOT), Augment Reality (AR), industrial robots, Artificial Intelligence 
	(AI) and other basic technologies.  For example, automation control is one of 
	the basic application and the the core is closed-loop control system. The 
	control process cycle is as low as millisecond level, so the system communication
	delay needs to reach millisecond level or even lower to ensure the realization 
	of precise control. There are three levels of real-time requirements for 
	industrial interconnection: factory level is about 1s, and process level 
	is 10~100ms, and the highest real-time requirement is motion control, 
	which requires less than 1ms.</t>
	
	<t>The future networks not only need to offer the Service Level Agreements 
	(SLA) guarantees such as low latency and jitter, low packet loss and high 
	reliability, but also need to support the precise services such as flexible 
	resource allocation and service isolation. This document proposes a set of 
	performance requirements and precise properties for Precise Transport Networking in 
	various industries such as 5G networks.</t>
  
   </section>

    <section title="Conventions used in this document">	 	
    <section title="Terminology">
	<t>The terminology is defined as <xref target="RFC8655"></xref>.</t>
   </section>
   
   <section title="Requirements Language">
    <t>The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
    "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and
    "OPTIONAL" in this document are to be interpreted as described in BCP
    14 <xref target="RFC2119"></xref> <xref target="RFC8174"></xref> when,
    and only when, they appear in all capitals, as shown here.</t>
    </section>
	
   </section>
   <section title="Terms of Precise Transport Networking">
   
    <t>IEEE 802.1 Time-Sensitive Networking (TSN) has been proposed to provide 
	bounded latency and jitter in L2 LAN networks. According to <xref target="RFC8655"></xref>, 
	Deterministic Networking (DetNet) operates at the IP layer and delivers 
	service with extremely low data loss rates and bounded latency. </t>
	
    <t>However, under the existing IP network architecture with statistical 
	multiplexing characteristics, the existing deterministic technologies are 
	facing long-distance transmission, queue scheduling, dynamic flows and 
	other controversial issues as described in [xiong-rtgwg-precise-tn-problem-statement]. 
	And besides precise latency, jitter, and packet loss, more other precise 
	and deterministic properties and performances should be provided such 
	as flexible resource allocation and service isolation and so on.</t>

    <t>Precise Transport Networking is defined to provide precise SLA guarantees such 
	as latency, jitter, packet loss rate, reliability, and precise control such 
	as flexible resource allocation and service isolation and more other precise
	services intelligently and dynamically. The purpose of the Precise Transport Networking 
	is based on the hierarchical structure of the transport network, taking advantage
	of the existing technologies including the flexible precise tunnels technology
	and the deterministic mechanisms, to support the end-to-end precise service 
	through the characteristics of slicing pieces, hard isolation and preemption
	characteristics, so as to achieve the high-precision of the future networks.</t>
   
   </section>
   <section title="Requirements of Precise Transport Networking">
   
   <section title="Precise Latency, Jitter, and Packet Loss">
   
    <t>It is required to provide precise Latency, jitter and packet loss dynamically
	and flexibly in all scenarios for each characterizd flow.</t>

    <t>The precise requirements of latency includes bounded latency and low latency. 
	The precise requirements of jitter includes bounded jitter and low jitter. 
	So the precise requirements of latency and jitter may be the combination of 
	latency and jitter, typically including bounded latency and low jitter, low 
	latency and bounded latency, and so on.</t>
  
   </section>
   
   <section title="Precise SLA Guarantees for Converged Networks">

    <t>It is required to provide precise SLA guarantees for converged networks 
    including computing and network convergence, lossless and network convergence, 
    etc.</t>
   
    <t>In some scenarios, such as MEC, it is required to provide precise computing 
    for Controlized CFN/APN. Other resources such as computing resources, energy 
    consumption should be considered. And the utilization and optimization of network 
    resources are extremely important.</t>
  
   </section>
   
   <section title="Precise Resource Allocation">
   
    <t>As described in <xref target="RFC8655"></xref>, the primary means by which DetNet achieves its QoS
	assurances is to reduce, or even completely eliminate, packet loss by the 
	provision of sufficient buffer storage at each node. But it can not be achieved 
	by not sufficient resource which can be allocated due to practical and cost 
	reason. The existing solutions can not achieve the precise resource allocation.</t>

    <t>Precise resource allocation is required along with the explicit path with
	more SLA guarantee parameters like bandwidth, latency, packet loss and so on.  
	The existing technologies such as FlexE and SR tunnels should be taken
	into consideration.</t>
   
   </section>
   
   <section title="Precise Service Isolation">
   
   <t>It is required to provide precise service isolation for every flow. In some
   scenarios, such as intelligent electrical network, the isolation requirements
   are very important. For example, the automatic operation or control of a process 
   or isochronous data and service with different priorities need to meet the 
   requirements of hard isolation.  In addition to the requirements of delay and 
   jitter, the differential protection (DP) service needs to be isolated from other 
   services and hard isolated tunnel is required. </t>
  
   </section>
   
   <section title="Precise OAM">
   
    <t>It is required to consider precise service performance detection and 
    perception, service support and recovery mechanisms, such as millisecond 
    level service monitoring, 0.0001% packet loss awareness, etc. The existing 
    solutions also do not consider the statistics, analysis and reporting of 
    service performance.</t>

    <t>Precise OAM is required including service monitoring, perception, performance
	statistics, precise service support and recovery mechanism, etc. The OAM 
	mechanisms should be taken into consideration such as In-band OAM, iOAM and
	so on.</t>

   
   </section>

   
   </section>
   
   
   <section title="Security Considerations">
    <t>TBA</t>
   </section>

    <section anchor="Acknowledgements" title="Acknowledgements">
    <t>TBA</t>
    </section>
	
	<section anchor="IANA" title="IANA Considerations">
	<t>TBA</t>
    </section>

	
  </middle>

  <!--  *****BACK MATTER ***** -->

  <back>
  
    <references title="Normative References">
    <?rfc include='reference.RFC.2119'?>
	<?rfc include='reference.RFC.8655'?>
	<?rfc include='reference.RFC.8174'?>

    </references>
        
  </back>
</rfc>
